Looks very similar to what i'm experiencing for one year now. Constantly feeling of something is stuck in my throat (cotton balls is a good description of the feeling) or some fluids are in there, other symptom i experienced too where like you fatique and lethargy (something that look similar to hypoglycemia, it happen after the meal for me) headaches, mack of sexdrive too (about his, as we are in the same case, i think we could find a solution together

ahahaha, just jocking

). I experienced some sore in the back and in the ribs. My GP thought that was reflux related and i'd some treatment about that (it's the third time he give me reflux treatment, but don't feel better, no relief).
One years ago, in the begining of all this, he prescribe me zoloft because he thought the problem i'd (throat and ribs sore) came frome anxiety/depression (but i don't think so now, i'll talk to him to stop it). So perhaps zoloft is giving me the fatigue/lethargy symptom, i don't know.
I passed some exams prescribed by my GP, but nothing special about the result, all looks to be ok
I think i know what you're experiencing and i hope you'll feel better very soon
P.S. Hope my english is understandable, i'm french